Naslov
The posibility of applying aerial photographs from cyclical aerial survey in the Republic of Croatia to forest management

Autori
Pernar, Renata ; Klobučar, Damir ; Kušan, Vladimir

Izvornik
Glasnik za šumske pokuse (0352-3861) 40 (2003); 113-167

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
remote sensing; aerial photographs; cyclic aerial survey; geographical information system (GIS); orthophotograph; digital terrain model (DTM); forest management

Sažetak
As the application of remote sensing methods to forestry is not satisfactory, this paper will discuss the possibilities of using aerial photographs from cyclic aerial survey in the Republic of Croatia in forest management. Photographs from cyclic aerial survey were selected for reasons of their availability on the market at a very reasonable price, unlike the commissioned recordings which considerably increased the cost of using remote sensing methods in the past. The images are black-and-white aerial photographs at an approximate scale M ≈ 1:20, 000 m and an overlap accuracy of 60%. The paper was based on the following guidelines: work rationalisation, the possibility of applying new technologies and lowered costs of data collection. The introductory part gives an overview of the development of the science of forest management and its links with forest mapping, remote sensing and the construction of the GIS model. A review of past research is also given entailing stand volume estimation and the importance and use of digital terrain models in modern forestry. The set goals are achieved through a qualitative and quantitative analysis of a model that consists of a stereomodel, a digital orthophotograph and a digital terrain model. Qualitative analysis involves the detection of all differentiating contents that may purposefully substitute taxation (management) field activities related to internal forest division by using remote sensing methods. A brief survey is given on the possibility of using models in other fields on pragmatic bases. The construction of a digital orthophoto and the possibilities of its application are also given. Orthophotographs are recommended for every management plan (regular revisions), preferably with larger-scale images. Quantitative analysis is based on the following five methods of stand volume estimation per hectare: I with Špiranec's growth-yield tables II with normal models according to ecological-management types III with classifying compartments according to management and age class and site quality using a referent compartment IV with classifying compartments according to management and age class without a referent compartment V with terrestrially measured maximal, minimal and average growing stock per hectare. Based on the obtained results and suitability for operational application, the 1st method with Špiranec's growth-yield tables was found to be the most acceptable. This method can also be used in forestry operative, especially in forest management. Other methods of volume estimation (based on investigation and results) are also worth considering and have their place in remote sensing of growing stocks. This refers primarily to the 2nd estimation method with normal models according to ecological-management types.

Izvorni jezik
Engleski

Znanstvena područja
Šumarstvo

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